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authorMichał Mirosław <mirq-linux@rere.qmqm.pl>2019-07-22 20:55:27 +0200
committerWolfram Sang <wsa@the-dreams.de>2019-08-01 22:24:16 +0200
commitd12e3aae160fb26b534c4496b211d6e60a5179ed (patch)
tree894ef1f43b93686b8c9f7fdc9a789ba660b305d1 /drivers/i2c
parentfd01eecdf9591453177d7b06faaabef8c300114a (diff)
i2c: at91: disable TXRDY interrupt after sending data
Driver was not disabling TXRDY interrupt after last TX byte. This caused interrupt storm until transfer timeouts for slow or broken device on the bus. The patch fixes the interrupt storm on my SAMA5D2-based board. Cc: stable@vger.kernel.org # 5.2.x [v5.2 introduced file split; the patch should apply to i2c-at91.c before the split] Fixes: fac368a04048 ("i2c: at91: add new driver") Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Tested-by: Raag Jadav <raagjadav@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-at91-master.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index e87232f2e708..a3fcc35ffd3b 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c
@@ -122,9 +122,11 @@ static void at91_twi_write_next_byte(struct at91_twi_dev *dev)
writeb_relaxed(*dev->buf, dev->base + AT91_TWI_THR);
/* send stop when last byte has been written */
- if (--dev->buf_len == 0)
+ if (--dev->buf_len == 0) {
if (!dev->use_alt_cmd)
at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
+ at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_TXRDY);
+ }
dev_dbg(dev->dev, "wrote 0x%x, to go %zu\n", *dev->buf, dev->buf_len);
@@ -542,9 +544,8 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
} else {
at91_twi_write_next_byte(dev);
at91_twi_write(dev, AT91_TWI_IER,
- AT91_TWI_TXCOMP |
- AT91_TWI_NACK |
- AT91_TWI_TXRDY);
+ AT91_TWI_TXCOMP | AT91_TWI_NACK |
+ (dev->buf_len ? AT91_TWI_TXRDY : 0));
}
}